If 3x + 7y = 8x − 18y and y 7, then which of the following must be

Question

If 3x + 7y = 8x − 18y and y > 7, then which of the following must be true? A) x < 7/5 B) x < 5 C) x > 18 D) x < 35 E) x > 36

sv9154 · Answer

If 3x+7y=8x-18y;y>7 then 25y=5x and x=5y and if y>7 then x should be greater than 35 so only E fits in. How could it be c?

d999 · Answer

neither x or y is said to be an integer so y could be 7.1, making x= 35.5

E would not hold true in such a case.

dhawalsachdeva · Answer

3x + 7y = 8x - 18y

Therefore, x = 5y

We are given, y>7
I.e. x/5 > 7
So x>35

Hence it will be greater than 18 too. So, OA is C.

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Jaya6 · Answer

Hey, can someone explain how and why is x>18? It seems possible for x to be >36 i,e option E.

Bunuel · Answer

It's the other way around.

3x + 7y = 8x − 18y and y > 7 gives x > 35. Since x > 35 then it must also be more than 18.

To understand the underline concept better practice other  Trickiest Inequality Questions Type: Confusing Ranges .

Kinshook · Answer

Asked: If 3x + 7y = 8x − 18y and y > 7, then which of the following must be true?

5x = 25y
x = 5y > 5*7 = 35
x>35>18

IMO C

G-Man · Answer

If X>18 is the answer

Can we consider 19 or 20 as one of the potential values for x

By solving the equation, we get X should be > 35

Bunuel · Answer

No. x cannot 19 or 20 because when we solve 3x + 7y = 8x − 18y and y > 7 we get x > 35. So, x MUST be more than 35. Since x is more than 35 than it's naturally more than 18 too.

To understand the underline concept better practice other  Trickiest Inequality Questions Type: Confusing Ranges .

samarpan.g28 · Answer

This is a trick question. It is not mentioned whether x and y are integers or not. Once we get x=5y, we can consider y=7.1, which gives x=35.5. By looking at the options, we must think E is correct, but C is true here too. Therefore, by checking the options thoroughly, we have to answer these inequalities. C is correct because if x=35.5, then x>18 is definitely true.

bumpbot · Answer

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If 3x + 7y = 8x − 18y and y > 7, then which of the following must be

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